Cutting tool for tissue surgical resection

ABSTRACT

A cutting tool for tissue surgical resection instruments, such as electric or ultrasonic bistoury, includes a connector element ( 5 ) supported in its upstream portion by the bistoury, a thin cutting element ( 7 ) integral with the connector element ( 5 ), and forming a plane, and a guide element ( 15 ) spaced apart from the cutting element ( 7 ) by a distance (b) equal to the thickness of the tissue elements to be removed and designed, during the cutting procedure, to be urged in contact with the surface ( 1 ) thereof. The guide element ( 15 ) is located in the cutting element plane, and its surface ( 1 ) adapted to be urged in contact with the tissues is larger than the corresponding surface of the cutting element ( 7 ).

This application is a 371 of PCT/FR01/01886 Jun. 15/2001 and claimspriority from France 00/07643 Jun. 15/2000.

BACKGROUND OF THE INVENTION

The present invention relates to a cutting tool intended for thesurgical resection of tissues and more principally to ade-epidermization.

It is known that such a surgical act, which is effected most of the timeby plastic surgeons, consists in removing the superficial layer of theskin, taking care to respect the subjacent vascularization following itscourse in the dermis. This surgical act, which is particularly delicateto carry out, is effected by using various blunt instruments of scissorsor scalpel type. This technique is delicate, particularly by reason ofthe difficulty that there is to ensure a removal of the dermis which isregular in thickness.

The instruments used in the prior state of the art are not able toensure such a regularity of the removed dermis.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome these drawbacks byproposing a cutting tool for bistoury which, without requiringparticular skill, ensures, virtually automatically, a removal of asuperficial layer of tissue which is regular in thickness.

The present invention thus has for its object a cutting tool intendedfor tissue surgical resection instruments, such as in particularelectric or ultrasonic bistouries, of the type comprising a connectorelement which is supported in its upstream portion by the bistoury, athin cutting element integral with the connector element, and forming aplane, and a guide element spaced apart from the cutting element by adistance equal to the thickness of the tissue elements to be removed andwhich is designed, during the cutting procedure, to be urged in contactwith the surface thereof, characterized in that the guide element islocated in the cutting element plane, and its surface adapted to beurged in contact with the tissues is larger than the correspondingsurface of the cutting element.

The guide element and the cutting element will preferably havecross-sections which are at least partly circular and the radius ofcurvature of the guide element will be greater than that of the cuttingelement.

Furthermore, the guide element may be a cylindrical element whose axiswill be parallel to that of the cutting element.

The guide element may be constituted by one or more rotary elementsadapted to roll on the tissues to be removed when they are displaced onthese latter. Such rotary elements may present a certain noteworthycoefficient of friction with respect to the tissue to be removed, which,as has been observed, improves regularity of the displacement of thecutting element.

The guide element will preferably be constituted by a cylindricalelement whose axis will be parallel to that of the cutting element.

In one form of embodiment of the invention, which is simple andinexpensive to implement, the blade will be constituted by a metal wirebent to as to form a loop of substantially rectangular shape of whichone of the sides will constitute the cutting element and the oppositeside will constitute the guide element. This latter element may becoated with an insulating material.

In another form of embodiment of the invention, the cutting tool willcomprise means for adjusting the distance existing between the cuttingelement and the guide element, which will enable the surgeon to effect,with the aid of the same tool, removals of different thicknesses.

This cutting tool is intended in particular to equip an electricbistoury but it may also be used on other types of bistouries such as inparticular ultrasonic bistouries.

When the bistoury is an electric bistoury, the cutting element will bein electrical connection with the bistoury and the guide element willnot be in electrical connection therewith. In that case, the guideelement may either be made of an insulating material or be made of aconducting material provided with insulating means.

It is known that de-epidermization may be effected for differentpurposes and in particular for purposes of aesthetic and reconstructivesurgery. It is also carried out in order to avoid the formation ofepidermic cysts in the event of turning-in of a musculo-cutaneous flap,in the case of a mammary reconstruction particularly when the flap isturned in under the cutaneous envelope of the breast after ablation ofthe glandular tissues. Moreover, in this same domain, it is known that,when an internal mammary prosthesis is fitted, one of the complicationswhich sometimes arises is the formation of a peri-prosthetic fibrousshell which, in the course of time, brings about a loss of suppleness ofthe breast as well as a deformation thereof. The treatment usuallycarried out consists in an exeresis of this shell by repeating theincision through which the prosthesis was fitted and which, foraesthetic reasons, is the smallest possible.

The present invention is more particularly interesting in this domain ofsurgery, since it makes it possible to ensure the exeresis of such ashell in particularly easy, regular and efficient manner.

Furthermore, the present invention is particularly well adapted toeffecting resections under endoscopic control (hysteroscopy, cystoscopy)of the internal part of a hollow organ and in particular of the uterus,bladder or digestive tube, insofar as it allows the surgeon to be sureof not hollowing out to too great a depth.

The cutting tool according to the invention may be used with unipolarelectric bistouries, but also with bipolar electric bistouries. To thatend, the tool may comprise connection means making it possible toconnect, on the one hand, the cutting element to one current supply poleand, on the other hand, conducting elements close to the cutting elementto the other supply pole.

BRIEF DESCRIPTION OF THE DRAWINGS

Various forms of embodiment of the present invention will be describedhereinafter by way of non-limiting examples, with reference to theaccompanying drawings, in which:

FIG. 1 is a view in section of a cutting tool for electric bistouryaccording to the invention, which is disposed perpendicularly to theplane of a skin surface which it is desired to de-epidermize.

FIG. 1 a is a view in transverse section of the cutting tool shown inFIG. 1 along line Ia-Ia thereof.

FIG. 2 is a partial longitudinal sectional view along a planeperpendicular to a skin surface to be de-epidermized, of a variantembodiment of the invention in which the thickness of the tissues to beremoved is adjustable.

FIG. 3 is a view on a smaller scale of a cutting tool for bistouryaccording to the invention, of non-adjustable type.

FIG. 3 a is a view in section of the tool shown in FIG. 3 along lineIIIa-IIIa thereof.

FIG. 3 b is an enlarged partial sectional view of the tool shown in FIG.3 a.

FIG. 4 is a view in perspective of a variant embodiment of a cuttingtool according to the invention.

FIG. 4 a is a schematic view in section of another example ofapplication of the cutting tool for electric bistoury according to theinvention shown in FIG. 4.

FIG. 5 is a partial view in perspective of a cutting tool according tothe invention intended for use on a bipolar bistoury.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 1 a show views in section, along a plane perpendicular to askin surface 1, of a cutting tool 3 which is intended to be connected toan electric bistoury (not shown in the drawing). This cutting tool 3thus comprises a rod 5 of stainless steel wire which is bent in itslower part so as to form a perpendicular arm 7. This arm 7 has a lengtha which corresponds to the working width of the tool 3. The arm 7terminates in a 90° bend extending in a second arm 9 parallel to the rod5 and itself terminating in another right-angled bend so as to form anarm 11 parallel to the arm 7 and of the same length a as the latter. Theend of the arm 11 comes into contact with the rod 5 and is fixedthereon, for example by means of welding spots 13. A guide element 15,constituted by an insulating and rigid cylinder, is threaded on the arm11 and is mounted to rotate thereon. This guide element 15 definesbetween its periphery and the upper face of the arm 7 a space ofdistance b which corresponds, as explained hereinafter, to the thicknessof the tissue which it is desired to remove.

The end of the rod 5 is connected to means, not shown in the drawing,for fixation of an electric bistoury of unipolar type.

Under these conditions, the bistouri according to the invention operatesas indicated hereinafter. The means for supplying current to theelectric bistoury being connected, the surgeon brings the arm 7 intocontact with the patient's skin and drives his cutting tool until theguide element 15 comes into contact with the upper surface 1 of theskin. It then remains for the surgeon to displace the bistoury in thedirection V so as to create, during this displacement, a cut-out 17 inthe tissues, thus forming a flap of epidermis 19 of regular thickness b.

In an interesting form of embodiment of the invention, the distance b isadjustable, which makes it possible for the surgeon to use the samecutting tool for various interventions.

FIG. 2 shows for example such a form of embodiment. The cutting tool 3is thus constituted by a rod 20 which is connected to the bistoury bymeans not shown in the drawing, and which comprises a threaded zone 22on which is screwed an adjusting wheel 24. This wheel comprises an innerchamber in which is disposed a bush 25 which is threaded on the rod 20and which comprises in its upper part a flange 26 which has the effectof connecting it in translation with the wheel 24 while leaving it freeto rotate with respect thereto. The lower part of the rod 20 extendsdownwardly by a portion of arm 5 a which is made of stainless steel wireand which is bent at 90° in order to form a part 7 a intended toconstitute the cutting element of the tool. A guide element 15 a isconstituted by a rigid cylinder of plastics material which is mountedfor rotation about two end bosses 27 which are mounted for rotation intwo corresponding recesses provided in the bush 25.

For reasons of simplification, only the left-hand half of the cuttingtool 3 has been shown in FIG. 2, the other, right-hand half beingidentical thereto.

In order to adjust the thickness b of the tissue to be removed, it willsuffice for the practitioner to screw or unscrew the wheel 24 on thethreaded part 22 of the rod 20, which will have the effect of displacingit in the longitudinal direction of this rod and consequently of movingthe guide element 15 a towards or away from the cutting element 7 a ofthe tool 3 depending on the direction of rotation of the wheel 24.

The outer surface of the guide element will advantageously presentslight roughness, intended to create a sufficient adherence between itsouter surface and the surface 1 of the skin, so that, during thedisplacement V, the guide element does not slide on the surface of theskin but rolls thereon. In fact, it has been observed that, by thusimproving the adherence of the guide element on the surface of the skin,the regularity of the displacement of the cutting element was improvedat the same time. The roughness of the outer surface of the guideelement may be produced by any means, whether it be by sand-blasting orby granulometry made at moulding, etc.

In a simplified form of embodiment of the invention shown in FIG. 3, thecutting element is constituted by a stainless steel wire 29 which issupported by a bistoury head 32 and which is wound so as to form a loop.In this form of embodiment of the invention, the thickness b of the flapof removed tissue is fixed. To that end, the opposite sides 5 a of theloop and the side 7 a form the cutting element. The side 15 b oppositeto side 7 a constitutes the guide element and is consequently coatedwith an insulating material. This same insulating material is alsodeposited over a length 1 of the wire 29.

The cross-section of the guide element 15 b is moon-shaped, theconcavity being oriented upwardly and the radius R of its base beingmuch greater than the radius r of the cutting element. Under theseconditions, the outer surface of this guide element capable of cominginto contact with the tissues 1 is much larger than that of the cuttingelement 7 a, which has the effect of promoting its guiding and smoothdisplacement over the tissues 1.

This form of embodiment is particularly interesting due to its low costprice which will allow the practitioner to have available a set ofcutting tools of various width a and thickness b appropriate for thedifferent interventions that he wishes to carry out.

Of course, in certain forms of embodiment of the invention, the supportrod or rods 5 or 29 do not necessarily lie in the plane formed by thecutting element and the guide element, and may form any angle with saidplane. In particular, they may be perpendicular thereto as shown inFIGS. 4 and 4 a.

Thus, by way of example, when it is desired to effect a resection of aperi-prosthetic fibrous shell 36 which may be formed in the course oftime when an internal mammary prosthesis is fitted, and which bringsabout a loss of suppleness of the breast as well as a deformationthereof, an angle of 90° is made between said plane and the rod 29. Thisallows the cutting element of the bistouri to be introduced through anincision 38 of small dimensions and to eliminate this shell 36 by adisplacement substantially in the direction V′ of the cutting tool 3.Such a cutting tool may also be used in combination with an electricbistoury operating in bipolar mode.

FIG. 5 thus shows a cutting tool 3 comprising two metallic support arms40 which terminate in two insulating studs 42 made of ceramics, at thebase of which is fixed a U-shaped metallic cutting element 7 a. Betweenthe two studs 42 is disposed a guide element 15 a constituted by aninsulating cylinder mounted for rotation about its longitudinal axis. Inthis form of embodiment, one of the poles A for electrical energy supplyis connected to the arms 40 and the other pole B is connected to thecutting element 7 a, by two insulated conductors 37 which pass throughthe arms 40 and which are connected to each of the ends of the cuttingelement 7 a.

Such a cutting tool may be used in particular for various applicationsand in particular for effecting endoscopic resections in a salinemedium.

1. Cutting tool intended for tissue surgical resection instruments,comprising: a connector element (5, 5 a, 29) which is supported in itsupstream portion by a bistoury (32), a thin cutting element (7, 7 a)supported by an elongated portion (5 a) of the connector element that istransverse to the cutting element, a longitudinal axis (X-X′) of thecutting element and a longitudinal axis (Y-Y′) of the elongated portionof the connector element together defining a cutting element plane, anda guide element (15, 15 a, 15 b) spaced apart from the cutting element(7, 7 a) by a distance (b) equal to the thickness of the tissue to beremoved and which is designed, during the cutting procedure, to be urgedin contact with the surface (1) thereof, wherein a longitudinal axis ofthe guide element (15, 15 a, 15 b) is located in the cutting elementplane and wherein the guide element has a surface adapted to be urged incontact with the tissue that is larger than the corresponding surface ofthe cutting element (7, 7 a).
 2. Cutting tool according to claim 1,wherein the guide element (15, 15 a, 15 b) and the cutting element (7, 7a) have cross-sections which are at least partly circular and the radiusof curvature (R) of the guide element (15, 15 a, 15 b) is greater thanthat (r) of the cutting element (7, 7 a).
 3. Cutting tool according toclaim 2, wherein the guide element (15, 15 a 15 b) is a cylindricalelement whose axis is parallel to that of the cutting element (7, 7 a).4. Cutting tool according to claim 2, wherein the guide element ismoon-shaped in cross-section and has a concavity facing away from thecutting element.
 5. Cutting tool according to claim 1, wherein the guideelement (15, 15 a) comprises at least one rotary element adapted torotate when it is displaced over the surface (1) of the tissues to beremoved.
 6. Cutting tool according to claim 5, wherein the outer surfaceof the rotary element (15, 15 a) has a coefficient of friction higherthan a coefficient of friction of the tissues to be removed.
 7. Cuttingtool according to claim 1, wherein the cutting element (7, 7 a) is inelectrical connection with the bistoury (32), and the guide element (15,15 a, 15 b) is not in electrical connection therewith.
 8. Cutting toolaccording to claim 7, wherein the guide element (15, 15 a, 15 b)comprises an insulating material.
 9. Cutting tool according to claim 1,comprising a metallic wire forming a loop of substantially rectangularshape, of which one of the sides (7 a) constitutes the cutting elementand the opposite side (15 b) constitutes the guide element.
 10. Cuttingtool according to claim 1, further comprising means (24, 25) foradjusting the distance (b) between the cutting element (7 a) and theguide element (15 a, 15 b).
 11. Cutting tool according to claim 1,further comprising a supply of current of bipolar type.
 12. Cutting toolaccording to claim 11, further comprising connection means (37) forconnecting the cutting element (7 a) to a first current supply pole (A)and connecting conducting elements (40) close to the cutting element (7a) to a second supply pole (B).